Reaction of 1-benzoselenopyrylium salts with grignard reagents: Formation of 2,4-disubstituted selenochromenes and their conversion into the corresponding 1-benzoselenopyrylium salts
selenopyrylium salts 1A and 2-phenyl-1-benzoselenopyrylium salts 1B with an alkyl(phenyl)magnesium halide resulted in nucleophilic addition at the C-4 position to give the corresponding2,4-disubstituted 4H-selenochromenes 2A and 2B in good yields, respectively. The obtained selenochromenes 2 were then easily converted into the 4-substituted 2-tert-butyl-1-benzoselenopyrylium salts 6A by treatment